One of the more frustrating jobs associated with leaf or grass raking is the need to periodically bend down (or to reverse the orientation of the rake and bring up its head) and reach for the rake head in order to manually clean away material which adheres to the rake tines in the areas between the prongs. This has to be done very often--perhaps after only one or two strokes in the case of certain types of leaves or vegetable garden matter, or when the matter is wet. Repeated stooping is fatiguing and may even be harmful to the back, particularly in the case of elderly gardeners. Bringing the rake head up is also unsatisfactory as it disrupts the normal flow and repetition of the rake strokes.
Much effort, apparently unsuccessful as measured by the lack of known commercialization, has therefore been directed toward developing a rake which is "self-cleaning;" which is to say, one which may be cleaned without the operator either having to stoop down or having to bring the rake head up.
Prior developments in this field will be generally illustrated by reference to the following U.S. Pat. Nos.:
______________________________________ U.S. Pat. No. Patentee Issue Date ______________________________________ 3,901,010 Pajunen 02/08/74 4,573,311 Ipema et al. 10/14/84 4,744,208 King 12/24/86 4,850,185 Dimon 06/25/89 ______________________________________
The above patents teach self-cleaning rakes all imply similar "self-cleaning" methods using attachments and other additions to the rake tines,prongs or teeth to clean them. None show means of cleaning without additions to the design of the rake prongs or teeth themselves.